Nonmetals anions formed

Nonmetal atoms form negative ions (anions—pronounced AN-i-ons) by gaining electrons. Consider, for example, what happens when atoms of the nonmetals chlorine and oxygen acquire electrons ... 

FIGURE C.7 The typical monatomic anions formed by a selection of elements in the periodic table. Notice how the charge on each ion depends on its group number. Only the nonmetals form monatomic anions under common conditions. 

Elements at the right of the p block have characteristically high electron affinities they tend to gain electrons to complete closed shells. Except for the metalloids tellurium and polonium, the members of Groups 16/VI and 17/VII are nonmetals (Fig. 1.62). They typically form molecular compounds with one another. They react with metals to form the anions in ionic compounds, and hence many of the minerals that surround us, such as limestone and granite, contain anions formed from non-metals, such as S2-, CO,2-, and S042-. Much of the metals industry is concerned with the problem of extracting metals from their combinations with nonmetals. 

B Aluminum forms an amphoteric oxide in which it has the oxidation state +3 therefore, aluminum is the element. 14.3B Hydrogen is a nonmetal and a diatomic gas at room temperature. It has an intermediate electronegativity (x — 2.2), so it forms covalent bonds with nonmetals and forms anions in combination with metals. In contrast, Group 1 elements are solid metals that have low electronegativities and form cations in combination with nonmetals. 

Nonmetals generally form negatively charged anions. 

C—All the other elements are nonmetals. Nonmetals usually form monatomic anions. 

Metals and hydrogen (a nonmetal) form positively charged cations. Nonmetals generally form negatively charged anions. 

For complete neutralization to take place, the proper amounts of acid and base must be present. The salt formed in the above reaction is NaCl. If the water were evaporated after completing the reaction, we would be left with common table salt. Sodium chloride is just one of hundreds of salts that form during neutralization reactions. While we commonly think of salt, NaCl, as a seasoning for food, in chemistry a salt is any ionic compound containing a metal cation and a nonmetal anion (excluding hydroxide and oxygen). Some examples of salts that result from neutralization reactions include potassium chloride (KCl), calcium fluoride (CaF ), ammonium nitrate (NH NOj), and sodium acetate (NaC2H302). 

Metal cations team up with nonmetal anions to form ionic compounds. What s more, the ratio of cations to anions within each formula unit depends on the charge assumed by the fickle transition metal. The formula unit as a whole must be electrically neutral. The rules you follow to name an ionic compound must accommodate the whims of transition metals. The system of Roman numerals or suffixes applies in such situations ... 

Elements usually form +1 cations in group 1, +2 cations in group 2, and +3 cations in group 3. Nonmetals usually form — 1 anions in group 7, —2 cations in group 6, and —3 anions in group 5. 

Think of forming an ionic compound as three steps (this is a simplification, as with all models) (1) removing an electron from the metal (2) adding an electron to the nonmeral and (3) allowing the metal cation and nonmetal anion to come together. 

Ionic compound (binary) a compound that results when a metal reacts with a nonmetal to form a cation and an anion. (13.1)... 

In contrast, the atoms of nonmetal elements form anions. Consider the example of oxygen, whose electron configuration is written as follows. 

In the previous section, the ionic bond and the reaction of metals with nonmetals to form ionic compounds were discussed. In this section, we examine the nature of the bond between atoms of two nonmetals, those elements to the right of the stair step on the periodic table. You will recall that in reactions between metals and nonmetals, metals lose electrons to form cations and nonmetals acquire them to from anions. But what if both elements are nonmetals Nonmetals, like O, Br, or N, do not lose electrons easily if anything, they prefer to acquire them. As a result, when two nonmetals bond to one another, they do so by sharing electrons forming bonds described as covalent. A covalent bond is a pair of electrons shared by two atoms. Compounds that are held together by covalent bonds are called covalent compounds, and they exist as individual molecules. Covalent bonding provides a second way for atoms to acquire an octet of electrons in their valence shells. The pair of electrons shared by two atoms becomes part of the valence shell of both atoms. 

In contrast to the BSD anion-forming reductions of BSD with the more electropositive metals, the oxidation of BSD with the most electronegative nonmetals does not lead to the BSD cation. The products of reaction of BSD with halogens (even at very low temperatures) are nitrogen and trimethyl-halosilane (50) [Eq. (56)]. 

For example, the anion formed from brom/ne is named bromide (brom-l-ide). Therefore, the compound formed from the metal calcium and the nonmetal bromine is named calcium bromide. 

In combination reactions, two substances, either elements or compounds, react to produce a single compotmd. One type of combination reaction involves two elements. Most metals react with most nonmetals to form ionic compounds. The products can be predicted from the charges expected for cations of the metal and anions of the nonmetal. For example, the product of the reaction between aluminum and bromine can be predicted from the following charges 3-1- for aluminum ion and 1— for bromide ion. Since there is a change in the oxidation numbers of the elements, this type of reaction is an oxidation-reduction reaction ... 

It is essential to understand that isolated atoms do not form ions on their own. Most commonly, ions are formed when metallic elements combine with nonmetallic elements. As we will discuss in detail in Chapter 8, when metals and nonmetals react, the metal atoms tend to lose one or more electrons, which are, in turn, gained by the atoms of the nonmetal. Thus reactions between metals and nonmetals tend to form compounds that contain metal cations and nonmetal anions. We will have more to say about these compounds later. 

Thus the reaction of a metal with a nonmetal to form an ionic compound involves the transfer of one or more electrons from the metal (which forms a cation) to the nonmetal (which forms an anion). This tendency to transfer electrons from metals to nonmetals is the third driving force for reactions that we listed in Section 8.1. A reaction that involves a transfer of electrons is called an oxidation-reduction reaction. 

Nonmetals lack metallic luster and are generally poor conductors of heat and electricity. Several are gases at room temperature. Compounds composed entirely of nonmetals are generally molecular. Nonmetals usually form anions in their reactions with metals. Nonmetal oxides are acidic they react with bases to form salts and water. Metalloids have properties that are intermediate between those of metals and nonmetals. 

Soluble ionic compounds are strong electrolytes. (Sections 4.1 and 4.3) Thus, CaCl2 consists of metal cations (Ca ) and nonmetal anions (Cl ). When completely dissociated, each CaCl2 unit forms three ions (one Ca " and two Cl ). Hence, the total concentration of ions in the solution is (3)(0.0397 M) = 0.119 M, and the calculated osmotic pressure is... 

---